threetoone = {"Ala": 'A', "Cys": 'C', "Asp": 'D', "Glu": 'E', "Phe": 'F', "Gly": 'G', "His": 'H', "Ile": 'I', "Lys": 'K', "Leu": 'L', 
              "Met": 'M', "Asn": 'n', "Pro": 'P', "Gln": 'Q', "Arg": 'R', "Ser": 'S', "Thr": 'T', "Val": 'V', "Trp": 'W', "Tyr": 'Y'}
onetothree = {}

if __name__ == '__main__':
    for item in threetoone:
        onetothree.update(dict({threetoone[item]: item}))
